Jim Draeger cringes when he sees some of the things that people have done to ranch houses in the name of improvement.

"They're making them into neo-Victorian houses," the architectural historian laments. "They see these shows on television that promote the idea that your house's value is based on how trendy it is. What people call 'home improvement' is a bigger threat to the ranch house than teardowns."

So, how can you remodel a ranch to suit today's lifestyles without destroying the character of your house?

"Good remodelings and alterations are contextual," says Draeger, who works for the Wisconsin Historical Society. "They respect the bones of a building and don't try to fight it."

In their 2003 book for Taunton Press, the handsomely illustrated "Updating Classic America: Ranches," Milwaukee authors Louis Wasserman and Caren Connolly offer myriad suggestions, such as turning smaller bedrooms into walk-in closets, adding skylights and floor-to-ceiling windows to increase natural light or putting a home office or master bedroom addition above a garage.

Jim Brown, publisher of Atomic Ranch magazine, advises ranch owners to preserve as much original fabric as possible, as well as the horizontality that defines the style.

"You can put on an extra story or add on to a small kitchen and still respect the intent of the design," he says. "But don't brick over a glass wall. And while in our heart of hearts we'd prefer preservation of even the original Formica, you can get away with adding granite countertops or even concrete."

The best advice, he says, is to live in a house for a year or so "before you impose your 21st-century thoughts on it. Maybe the house was correct and you just have to change your perception of what you need."

Jeff and Barbara Joseph can attest to how the designers of vintage ranches often got it right the first time. Two years ago, with the help of Dick Froze of Froze Design Build Inc., they undid the interior mistakes imposed by a 1975 addition to their stunning 1954 ranch.

The long, ground-hugging house is nestled into a three-acre, sloping lot overlooking a wooded backyard and the Milwaukee River. The late architect Elmer Johnson (1901-1990) designed it as a home for himself.

Johnson used reclaimed Douglas fir from a demolished box company warehouse throughout the 2,800-square-foot house and opened it up to nature with floor-to-ceiling window walls and skylights. Surrounded by greenery and bathed in sunlight, "you feel like you're living in a terrarium," says Barbara Joseph. "Outdoors is indoors."

It wasn't always that way. A previous owner's addition had chopped up Johnson's original open plan with walls between the living room, dining area and kitchen; the fir ceilings had also been darkened.

"When we bought the house in 1991," Barbara says, "it was like being in a cave."

Froze's restoration removed the added walls, lightened the wood with a gray wash, updated the kitchen and tucked in new storage space. The result is a welcoming, light-filled living space that seems both contemporary and timeless.